Fuel pump

ABSTRACT

A fuel pump includes a pump part, a motor part, a motor casing, a motor cover, a terminal, and an electric connector part. The terminal is electrically connectable to an external connector for electricity supply. The electric connector part is disposed at an end portion of the motor cover located on the opposite side from a fitted end of the motor cover which is fitted with a housing, and includes a side surface which is slidably in contact with the external connector to determine a fitting position of the electric connector part relative to the external connector, a bottom face from which the terminal rises up, and an opening which is formed on the side surface to communicate between inside and outside of the electric connector part. The bottom face is an inclined surface whose height becomes lower in a direction from generally a center of the motor cover toward the opening.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on and incorporates herein by referenceJapanese Patent Application No. 2010-194456 filed on Aug. 31, 2010.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fuel pump that drives its pump partby driving force of its motor part to suction and pressurize fuel.

2. Description of Related Art

A fuel pump that supplies fuel to an internal combustion engine isknown. The fuel pump pressurizes fuel suctioned from a fuel tank by itspump part, and supplies the fuel to the engine. In the fuel pump, anelectric current supplied via its electric connector part flows througha coil, so that a rotor, around which the coil is wound, rotates todrive the pump part. In JP-A-2008-243569, by changing a shape of a resinmember that supports a terminal of an electric connector part, acorrosion or short circuit of the terminal which is caused due to theresidue of fuel inside the electric connector part is prevented.

In the electrical connector described in JP-A-2008-243569, an openingfor discharging the fuel that remains in the electric connector partinto the outside is provided on a side surface of the electric connectorpart. However, if fuel remains away from the opening, or if the residualfuel becomes high-viscosity liquid as a result of the evaporation of itsvolatile matter content, the discharge of fuel from the opening becomesdifficult, and they remain inside the electric connector part.Particularly, because the liquid, whose impure substance has beencondensed due to the evaporation of volatile matter content, exhibitshigh conductivity, the terminal corrodes by a leak current between bothpoles, and eventually damage of the terminal is caused.

SUMMARY OF THE INVENTION

The present invention addresses at least one of the above disadvantages.

According to the present invention, there is provided a fuel pumpincluding a pump part, a motor part, a motor casing, a motor cover, aterminal, and an electric connector part. The pump part includes arotation member configured to suction and pressurize fuel. The motorpart includes a rotor coupled with a rotating shaft of the rotationmember to be capable of rotating the rotation member, a commutatorrotated together with the rotor to rectify an electric current suppliedto the rotor, and a housing accommodating the rotor and the commutator.The motor casing supports one end of the rotating shaft of the rotationmember. The motor cover is disposed at one end of the motor part in anaxial direction thereof and is fitted together with the housing so as tofix the motor casing. The terminal is disposed at an end portion of themotor cover located on an opposite side from a fitted end of the motorcover, which is fitted with the housing. The terminal is electricallyconnectable to an external connector for electricity supply. Theelectric connector part is disposed at the end portion of the motorcover located on the opposite side from the fitted end of the motorcover, and includes a side surface which is slidably in contact with theexternal connector to determine a fitting position of the electricconnector part relative to the external connector, a bottom face fromwhich the terminal rises up, and an opening which is formed on the sidesurface to communicate between inside and outside of the electricconnector part. The bottom face is an inclined surface whose heightbecomes lower in a direction from generally a center of the motor covertoward the opening.

According to the present invention, there is also provided a fuel pumpincluding a pump part, a motor part, a motor casing, a motor cover, aterminal, and an electric connector part. The pump part includes arotation member configured to suction and pressurize fuel. The motorpart includes a rotor coupled with a rotating shaft of the rotationmember to be capable of rotating the rotation member, a commutatorrotated together with the rotor to rectify an electric current suppliedto the rotor, and a housing accommodating the rotor and the commutator.The motor casing supports one end of the rotating shaft of the rotationmember. The motor cover is disposed at one end of the motor part in anaxial direction thereof and is fitted together with the housing so as tofix the motor casing. The terminal is disposed at an end portion of themotor cover located on an opposite side from a fitted end of the motorcover, which is fitted with the housing. The terminal is electricallyconnectable to an external connector for electricity supply. Theelectric connector part is disposed at the end portion of the motorcover located on the opposite side from the fitted end of the motorcover, and includes a side surface which is slidably in contact with theexternal connector to determine a fitting position of the electricconnector part relative to the external connector, a bottom face fromwhich the terminal rises up, and an opening which is formed on the sidesurface to communicate between inside and outside of the electricconnector part. The bottom face includes a groove in a direction fromgenerally a center of the motor cover toward the opening, the grooveconnecting to the opening.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with additional objectives, features andadvantages thereof, will be best understood from the followingdescription, the appended claims and the accompanying drawings in which:

FIG. 1 is a sectional view roughly illustrating a fuel pump inaccordance with a first embodiment of the invention;

FIG. 2 is a sectional view taken along a line II-II in FIG. 1 forillustrating enlarged vicinity of a brush;

FIG. 3A is a top view illustrating a motor cover of the fuel pump inaccordance with the first embodiment;

FIG. 3B is a front view of the motor cover viewed from a direction of anarrow IIIB in FIG. 3A;

FIG. 3C is a sectional view taken along a line IIIC-IIIC in FIG. 3A;

FIG. 4 is a sectional view taken along a line IV-IV in FIG. 3A forillustrating enlarged vicinity of a bottom face of an electric connectorpart;

FIG. 5 is a perspective view of a cross-section taken along a line V-Vin FIG. 3B for illustrating the motor cover of the fuel pump inaccordance with the first embodiment;

FIG. 6A is a top view illustrating a motor cover of a fuel pump inaccordance with a second embodiment of the invention;

FIG. 6B is a front view of the motor cover viewed from a direction of anarrow VIB in FIG. 6A;

FIG. 6C is a sectional view taken along a line VIC-VIC in FIG. 6A; and

FIG. 7 is a sectional view taken along a line VII-VII in FIG. 6A forillustrating enlarged vicinity of a bottom face of an electric connectorpart.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention will be described below with reference tothe accompanying drawings.

First Embodiment

A fuel pump 10 of a first embodiment of the invention is illustrated inFIG. 1. This fuel pump 10 is an in-tank pump that is disposed in a fueltank (not shown) of a vehicle. The fuel pump 10 supplies fuel inside thefuel tank to an engine. The fuel pump 10 includes a pump part 12 thatpressurizes the suctioned fuel, and a motor part 14 that drives the pumppart 12. The motor part 14 is a direct-current motor with a brush. Thefuel pump 10 includes a housing 16 having a generally cylindrical shape.A permanent magnet 18 is disposed annularly in the circumferentialdirection on an inner wall surface of the housing 16. A rotor 20 isdisposed radially inward of the permanent magnet 18 concentrically withthe annular permanent magnet 18.

The pump part 12 includes a casing main body 31, a casing cover 32, andan impeller 33 which is a rotation member. The casing main body 31 andthe casing cover 32 define a generally C-shaped pump passage 34. Theimpeller 33 is accommodated rotatably between the casing main body 31and the casing cover 32. The casing main body 31 and the casing cover 32are formed by, for example, die casting of aluminum.

The casing main body 31 is fixed in one end side of the housing 16 in anaxial direction thereof by press fitting. A pump part side bearing 35that rotatably supports a shaft 21, which is connected to the impeller33, is disposed at a central part of the casing main body 31.

The casing cover 32 is fixed to one end portion of the housing 16 bycalking, with the casing main body 31 covered in the cover 32. A thrustbearing 36 that limits axial displacement of the shaft 21 is fixed at acentral part of the casing cover 32. The casing cover 32 has a fuelinlet 38.

A motor casing 41 and a motor cover 42 are disposed at the other endportion of the housing 16, i.e., on the opposite side of the housing 16from the casing main body 31 and the casing cover 32. The motor casing41 is located between the motor cover 42 and the housing 16. The motorcasing 41 includes a connecting passage 44 that connects together a pumpchamber 22 and a fuel passage 43 of the motor cover 42. The motor casing41 defines a brush accommodating chamber 45 which accommodates a brush70 such that the brush 70 can be reciprocated in its axial direction, asillustrated in FIG. 2. The motor casing 41 defines the brushaccommodating chamber 45, in which the brush 70 is accommodated. Themotor casing 41 accommodates the brush 70, and a compression spring 75in its brush accommodating chamber 45.

As illustrated in FIG. 1, the motor cover 42 includes a fuel dischargepart 46 and an electric connector part 50 radially outward of the shaft21. The motor cover 42 is fixed to the housing 16 by calking. The fueldischarge part 46 includes the fuel passage 43 and a pressure regulatingvalve 48. The fuel passage 43 is opened or closed by a valve member 49of the pressure regulating valve 48. When the pressure of fuel insidethe fuel pump 10 becomes larger than a predetermined value, the valvemember 49 opens the fuel passage 43.

Terminals 60, 61 are provided for the electric connector part 50, whichis connected to the outside of the fuel pump 10. As illustrated in FIG.2, the terminals 60, 61 are electrically connected to a pigtail 71 via achoking coil 72 and a brush terminal 73. The pigtail 71 is electricallyconnected to a side surface of the surfaces, which constitute the brush70, that is located on the opposite side from a rotation center of theshaft 21.

As illustrated in FIG. 1, the rotor 20 is rotatably accommodated insidethe housing 16. One end portion of the shaft 21, which is integratedwith the rotor 20, is rotatably supported by the pump part side bearing35 in its radial direction; and the other end portion of the shaft 21 isrotatably supported by a motor part side bearing 37 in the radialdirection. A winding wire that constitutes a coil 23 is wound around anouter peripheral surface of the core 25, which is fixed to the shaft 21.A commutator 80 is formed in the shape of a circular disk, and disposedabove the rotor 20. More specifically, the commutator 80 is located atan end portion of the rotor 20 on its opposite side from the pump part12.

The electric connector part 50 will be described in detail. The electricconnector part 50 is provided on the opposite side of the center of themotor cover 42 from the fuel discharge part 46 as illustrated in FIGS.3A to 3C. The electric connector part 50 has a recessed shape with abottom because of its side surfaces 501, 502, 503, 504, which areslidably in contact with an external connector for electricity supply todetermine a fitting position between the electricity supply connectorand the electric connector part 50, and its bottom face 505, from whichfrom which the terminals 60, 61 are exposed to rise up. The electricconnector part 50 is provided with an opening 57 for the externalconnector, so as to be fitted together to the external electricitysupply connector. A direction of the opening 57 for the externalconnector is an upward direction which is the same direction as thedirection of an opening of the fuel discharge part 46. Arrows indicatingthe upward and downward directions in FIGS. 3A to 4 illustrate upwardand downward directions with the fuel pump 10 disposed in the fuel tank.

As illustrated in FIG. 4, an interior portion of the electric connectorpart 50 is divided into three parts: a terminal part 51 and twocommunication parts 53, 55 by a shape of the bottom face 505. Theterminal part 51 is located at generally the center of the electricconnector part 50. A terminal part bottom face 52 that serves as abottom face of the terminal part 51 is formed generally parallel to aplane perpendicular to the upward and downward directions. On theterminal part bottom face 52, the terminals 60, 61 for receiving theelectric power supply from the outside are disposed at intervals to passthrough the terminal part bottom face 52 in the upward and downwarddirections.

The communication parts 53, 55 are formed at both ends of the terminalpart 51 in a tangential direction of the motor cover 42 to be connectedto the terminal part 51. As illustrated in FIG. 3C, a communication partbottom face 54 serving as a bottom face of the communication part 53 isan inclined surface from the center of the motor cover 42 toward anopening 58. As well, a communication part bottom face 56 serving as abottom face of a communication part 55 located on the opposite side ofthe terminal part 51 from the communication part 53 is an inclinedsurface from the center of the motor cover 42 toward an opening 59.Heights of the communication part bottom faces 54, 56 become lower fromthe center of the motor cover 42 toward the openings 58, 59. On theother hand, height of the terminal part bottom face 52 does not changeregardless of its distance from the center of the motor cover 42 asdescribed above. Accordingly, as illustrated in FIG. 5, leveldifferences 531, 551 are formed respectively between the terminal partbottom face 52 and the communication part bottom faces 54, 56. Widths ofthe level differences 531, 551 become larger in a direction away fromthe center of the motor cover 42.

As illustrated in FIG. 3B, the two generally rectangular openings 58, 59are formed on an outer wall of the electric connector part 50. Theopenings 58, 59 communicate between the inside and outside of theelectric connector part 50. The openings 58, 59 are formed on radiallyoutward extension lines of the communication parts 53, 55, and thecommunication parts 53, 55 and the openings 58, 59 are connectedtogether. The openings 58, 59 are formed such that the heights of thecommunication part bottom faces 54, 56, and heights of lower ends of theopenings 58, 59 coincide with each other.

Operation of the fuel pump 10 of the first embodiment will be described.An electric current supplied to the terminal 60 from a power source (notshown) is fed to the commutator 80 through the brush terminal 73, thepigtail 71, and the brush 70. The electric current fed into thecommutator 80 is supplied to the coil 23 of the rotor 20. Upon rotationof the rotor 20 by the electric current supplied to the coil 23, theimpeller 33 rotates together with the rotor 20 and the shaft 21. Whenthe impeller 33 rotates, fuel is suctioned into the pump passage 34through the fuel inlet 38. The fuel suctioned into the pump passage 34is discharged from the pump passage 34 into the pump chamber 22 as aresult of application of kinetic energy to the fuel by vane grooves ofthe impeller 33. The fuel discharged into the pump chamber 22 issupplied to the outside of the fuel pump 10 through a surrounding areaof the rotor 20 and the fuel passage 43.

As a result of the increase of fuel in the fuel tank in the electricconnector part 50 with its opening 57 for the external connector formedupward, a part of fuel enters into the electric connector part 50. Onthe other hand, when a fluid level of fuel decreases as a result of theconsumption of fuel, the fuel, which has entered into the electricconnector part 50, moves from higher bottom faces toward lower bottomfaces along the communication part bottom faces 54, 56 connected to theopenings 58, 59, so as to be discharged into the outside of the electricconnector part 50.

Generally, fuel remains in an electric connector part due to increaseand decrease of fuel in a fuel tank. The residual fuel becomes liquidcontaining many involatile impure substances as a result of evaporationof its volatile matter content. The liquid including many impuresubstances does not easily move inside the electric connector partbecause of its high viscosity. Accordingly, the liquid is not easilydischarged even if there is an opening for discharging the fuel, whichhas entered into the electric connector part, into the outside.

In the fuel pump 10 of the first embodiment of the invention, thecommunication part bottom faces 54, 56, whose heights become loweroutward in a radial direction of the motor cover 42, are provided forthe electric connector part 50. The liquid including many impuresubstances that has remained inside the electric connector part 50 movestoward the openings 58, 59 along the inclined surfaces of thecommunication part bottom faces 54, 56 by the action of gravity. Then,the liquid is discharged into the outside of the electric connector part50 through the openings 58, 59. Accordingly, adhesion of impuresubstances contained in the residual liquid to the terminals 60, 61 canbe prevented. As a result, development of corrosion of the terminals 60,61, and eventually damage to the terminals 60, 61 can be prevented.

Second Embodiment

A second embodiment of the invention will be described with reference toFIGS. 5A to 7. The second embodiment is different from the firstembodiment in part of a shape of a communication part bottom face thatdefines a communication part, which communicates with a terminal part ofan electric connector part. The same numerals are used for indicatingsubstantially the same components as the first embodiment, and theirdescriptions are omitted. In the second embodiment, communication partbottom faces 64, 66 defining communication parts 63, 65 include groovesrespectively. Specifically, as illustrated in FIG. 7, V-shaped groovesare formed on the communication part bottom faces 64, 66 such that theirrecessed ridgelines 643, 663 are located in a downward direction. Thecommunication part bottom faces 64, 66 respectively include two bottomfaces, i.e., communication part center side bottom faces 641, 661 thatare formed on a terminal part 51-side of the recessed ridgelines 643,663; and communication part outer side bottom faces 642, 662 that areformed toward two side walls 501, 502 which constitute an electricconnector part 50. Each two bottom faces are inclined surfaces with thecorresponding recessed ridgelines 643, 663 being the lowest points.Therefore, the communication part center side bottom faces 641, 661, andthe communication part outer side bottom faces 642, 662 are connectedtogether respectively at the recessed ridgelines 643, 663.

Openings 68, 69 are connected to the V—shapes, which are constituted ofthe communication part center side bottom faces 641, 661 and thecommunication part outer side bottom faces 642, 662. Specifically, asillustrated in FIG. 6B, the V-shapes formed by the communication partcenter side bottom faces 641, 661 and the communication part outer sidebottom faces 642, 662 coincide with part of shapes of the openings 68,69. Thus, the shapes of the openings 68, 69 are generally pentagonsrespectively having one vertex at their lowest positions.

In the second embodiment, liquid that remains in the electric connectorpart 50 is collected at the recessed ridgelines 643, 663 along theinclined surfaces of the communication part center side bottom faces641, 661 and the communication part outer side bottom faces 642, 662.After that, the collected liquid is discharged into the outside of theelectric connector part 50 through the openings 68, 69. Since the fuelthat remains inside the electric connector part 50 is gatheredtemporarily around the recessed ridgelines 643, 663, even if the amountof remaining liquid is small as compared with the first embodiment, theliquid is easily discharged into the outside of the electric connectorpart 50.

Modifications of the above embodiments will be described. Firstly, inthe above first embodiment, the shape of the communication part bottomface is a planar inclined surface toward the opening. Alternatively, theshape of the communication part bottom face is not limited to this. Theshape of the communication part bottom face may be a curved surfacehaving a conical shape, a hemispherical shape, a radial shape, or thelike; and a gradient ratio of its inclination may be changed within thissurface.

Secondly, in the above second embodiment, a groove formed on thecommunication part bottom face is V-shaped at a generally centralposition of the communication part bottom face. However, the arrangementposition of the groove, the shape of the groove, the number of grooves,and height of a recessed ridgeline of the groove are not necessarilylimited to this.

Thirdly, in the above second embodiment, only the groove is formed onthe communication part bottom face. Alternatively, what is formed on thecommunication part bottom face is not exclusive to the groove. Acommunication part bottom face, on which the groove is combined with theinclined surface described in the above first embodiment, may beemployed.

Fourthly, in the above embodiments, the inclined surface or the grooveis formed on the communication part bottom face. However, a surface, onwhich the inclined surface or the groove is formed, is not limited tothe communication part bottom face. The inclined surface or the groovemay be formed also on the terminal part bottom face, through which theterminal is disposed.

Fifthly, in the above embodiments, the height of the communication partbottom face and the height of the lower end of the opening are set to bethe same. Alternatively, a positional relationship between thecommunication part bottom face and the opening is not necessarilylimited to this. Any positional relationship may be employed as long asthe height of the communication part bottom face is equal to or higherthan the height of the lower end of the opening.

Sixthly, in the above embodiments, the shape of the opening is generallyrectangular or generally pentagonal. However, the shape of the openingis not limited to this. The shape of the opening may be a shape thatconforms with the shape of the communication part bottom face, such as agenerally round shape or a generally polygon.

Lastly, in the above embodiments, the example of application of theimpeller having vane grooves to the rotation member of the pump part isdescribed. However, instead of the application of the impeller, anothertype of a pump, such as a Trochoid (registered trademark) pump or a gearpump, may be applied to the rotation member.

The embodiments of application of the invention to the in-tank pumpdisposed inside the fuel tank of the vehicle have been described above.Nevertheless, the invention is not by any means limited to suchembodiments, and may be embodied in various modes without departing fromthe scope of the invention.

To sum up, the fuel pump 10 of the above embodiments may be described asfollows.

The fuel pump 10 includes a pump part 12, a motor part 14, a motorcasing 41, a motor cover 42, a terminal 60 or 61, and an electricconnector part 50. The pump part 12 includes a rotation member 33configured to suction and pressurize fuel. The motor part 14 includes arotor 20 coupled with a rotating shaft 21 of the rotation member 33 tobe capable of rotating the rotation member 33, a commutator 80 rotatedtogether with the rotor 20 to rectify an electric current supplied tothe rotor 20, and a housing 16 accommodating the rotor 20 and thecommutator 80. The motor casing 41 supports one end of the rotatingshaft 21 of the rotation member 33. The motor cover 42 is disposed atone end of the motor part 14 in an axial direction thereof and is fittedtogether with the housing 16 so as to fix the motor casing 41. Theterminal 60 or 61 is disposed at an end portion of the motor cover 42located on an opposite side from a fitted end of the motor cover 42,which is fitted with the housing 16. The terminal 60 or 61 iselectrically connectable to an external connector for electricitysupply. The electric connector part 50 is disposed at the end portion ofthe motor cover 42 located on the opposite side from the fitted end ofthe motor cover 42, and includes a side surface 501, 502, 503, or 504which is slidably in contact with the external connector to determine afitting position of the electric connector part 50 relative to theexternal connector, a bottom face 54 or 56; 64 or 66 from which theterminal 60 or 61 rises up, and an opening 58 or 59; 68 or 69 which isformed on the side surface 501, 502, 503, or 504 to communicate betweeninside and outside of the electric connector part 50. The bottom face 54or 56; 64 or 66 is an inclined surface whose height becomes lower in adirection from generally a center of the motor cover 42 toward theopening 58 or 59; 68 or 69.

The bottom faces 54, 56 of the electric connector part 50 are inclinedsurfaces whose heights becomes lower from the generally center of themotor cover 42 toward the openings 58, 59. The liquid that remainsinside the electric connector part 50 moves toward the openings 58, 59having lower heights along the inclined surfaces formed on the bottomfaces 54, 56 of the electric connector part 50. Then, the liquid isdischarged from the openings 58, 59 into the outside of the electricconnector part 50. Accordingly, corrosion of the terminals 60, 61 causedby adhesion of impure substances contained in the residual liquid can beprevented.

A gradient ratio of an inclination of the inclined surface may changewithin the inclined surface. Specifically, the bottom faces 54, 56 ofthe electric connector part 50 are not the inclined surfaces having acertain gradient ratio in the whole regions thereof. Alternatively, anarbitrary gradient ratio may be set at an arbitrary position on each ofthe bottom faces 54, 56 of the electric connector part 50. Consequently,by forming the inclined surfaces 54, 56 having large gradient ratios atthe positions at which the liquid is more likely to remain, the residualliquid easily moves to be collected. As a result, the corrosion of theterminals 60, 61 due to attachments contained in the remaining liquidcan be prevented.

The bottom face 64 or 66 may include a groove in the direction fromgenerally the center of the motor cover 42 toward the opening 68 or 69.The groove may connect to the opening 68 or 69. By the formation ofgrooves on the bottom faces 64, 66 of the electric connector part 50from the generally center of the motor cover 42 toward the openings 68,69, the liquid that remains inside the electric connector part 50 can becollected at the lowest portions 643, 663 of the grooves. After that,the liquid collected at the lowest portions 643, 663 of the grooves isdischarged into the outside through their connecting openings 68, 69.Accordingly, even if the amount of liquid remaining inside the electricconnector part 50 is small, the liquid is easily removed, and corrosionof the terminals 60, 61 can be prevented.

A height of a recessed ridgeline 643 or 663 of the groove may becomelower in the direction from generally the center of the motor cover 42toward the opening 68 or 69. Consequently, the liquid gathered at therecessed ridgelines 643, 663 of the grooves moves toward the openings68, 69 having lower heights, and is discharged into the outside of theelectric connector part 50. As a result, the residual liquid can beefficiently discharged as compared with the grooves whose recessedridgelines 643, 663 have constant heights.

Additional advantages and modifications will readily occur to thoseskilled in the art. The invention in its broader terms is therefore notlimited to the specific details, representative apparatus, andillustrative examples shown and described.

What is claimed is:
 1. A fuel pump comprising: a pump part that includesa rotation member configured to suction and pressurize fuel; a motorpart that includes: a rotor coupled with a rotating shaft of therotation member to be capable of rotating the rotation member; acommutator rotated together with the rotor to rectify an electriccurrent supplied to the rotor; and a housing accommodating the rotor andthe commutator; a motor casing that supports one end of the rotatingshaft of the rotation member; a motor cover that is disposed at one endof the motor part in an axial direction thereof and is fitted togetherwith the housing so as to fix the motor casing; a terminal that isdisposed at an end portion of the motor cover located on an oppositeside from a fitted end of the motor cover, which is fitted with thehousing, the terminal being electrically connectable to an externalconnector for electricity supply; and an electric connector part that isdisposed at the end portion of the motor cover located on the oppositeside from the fitted end of the motor cover and that includes: a sidesurface which is slidably in contact with the external connector todetermine a fitting position of the electric connector part relative tothe external connector; a bottom face from which the terminal rises up;and an opening which is formed on the side surface to communicatebetween inside and outside of the electric connector part, wherein thebottom face is an inclined surface whose height becomes lower in adirection from generally a center of the motor cover toward the opening.2. The fuel pump according to claim 1, wherein a gradient ratio of aninclination of the inclined surface changes within the inclined surface.3. The fuel pump according to claim 1, wherein the bottom face includesa groove in the direction from generally the center of the motor covertoward the opening, the groove connecting to the opening.
 4. The fuelpump according to claim 3, wherein a height of a recessed ridgeline ofthe groove becomes lower in the direction from generally the center ofthe motor cover toward the opening.
 5. A fuel pump comprising: a pumppart that includes a rotation member configured to suction andpressurize fuel; a motor part that includes: a rotor coupled with arotating shaft of the rotation member to be capable of rotating therotation member; a commutator rotated together with the rotor to rectifyan electric current supplied to the rotor; and a housing accommodatingthe rotor and the commutator; a motor casing that supports one end ofthe rotating shaft of the rotation member; a motor cover that isdisposed at one end of the motor part in an axial direction thereof andis fitted together with the housing so as to fix the motor casing; aterminal that is disposed at an end portion of the motor cover locatedon an opposite side from a fitted end of the motor cover, which isfitted with the housing, the terminal being electrically connectable toan external connector for electricity supply; and an electric connectorpart that is disposed at the end portion of the motor cover located onthe opposite side from the fitted end of the motor cover and thatincludes: a side surface which is slidly in contact with the externalconnector to determine a fitting position of the electric connector partrelative to the external connector; a bottom face from which theterminal rises up; and an opening which is formed on the side surface tocommunicate between inside and outside of the electric connector part,wherein the bottom face includes a groove in a direction from generallya center of the motor cover toward the opening, the groove connecting tothe opening.
 6. The fuel pump according to claim 5, wherein a height ofa recessed ridgeline of the groove becomes lower in the direction fromgenerally the center of the motor cover toward the opening.